Conventionally, a fastener stringer (knitted fastener stringer) for a knitted slide fastener which is obtained by knitting a continuous fastener element into an element attaching portion along a length direction of a fastener tape at the same time as knitting the fastener tape by using a double warp knitting machine having two rows of needle beds like for example a double raschel knitting machine has been known.
One example of this knitted fastener stringer is disclosed in JP H08-228813 A (Patent Document 1). A knitted fastener stringer described as one of embodiments in this Patent Document 1 is shown in FIGS. 10 and 11. In FIG. 11, a knit structure is illustrated with knitted stitches loosened to make the knit structure in an element attaching portion of a fastener tape easy to understand.
A knitted fastener stringer 50 of this Patent Document 1 comprises a fastener tape 51 having a warp knit structure and a continuous (coil-shaped) fastener element 52 knitted into an element attaching portion 51a which is formed in a longitudinal side edge portion of the fastener tape 51.
A ground structure of the fastener tape 51 is configured by a chain stitch yarn 61 (1-0/0-0/0-1/1-1), a tricot stitch yarn 62 (1-2/1-1/1-0/1-1), and an weft inserted yarn 63 (0-0/2-2/4-4/2-2) which is inserted in a zigzag pattern while striding across four wales of the fastener tape 51.
A fixing chain stitch yarn 64 (0-1/1-0/1-0/0-1) having a double knit structure of a back needle row (B) and a front needle row (F) is knitted into two wales disposed on a tape main body portion side out of three wales constituting the element attaching portion 51a respectively.
In this fixing chain stitch yarn 64, as shown in FIG. 11, a first needle loop 64a (back side needle loop) formed in the back needle row is knitted into the ground structure of the element attaching portion 51a so as to be entangled with a needle loop of the above chain stitch yarn 61 and a needle loop of the above tricot stitch yarn 62, and forms the dense ground structure.
Also, a second needle loop 64b (front side needle loop) of the fixing chain stitch yarn 64 formed in the front needle row presses and fixes upper and lower leg portions of the fastener element 52 to the ground structure of the element attaching portion 51a by striding across the pair of upper and lower leg portions of the fastener element 52 and being entangled with the second needle loop 64b to be subsequently formed.
In this particular case, as shown in FIGS. 10 and 11, two first and two second needle loops 64a, 64b are formed in the fixing chain stitch yarn 64 at each one pitch in a tape length direction of the fastener element 52, and the upper and lower leg portions of the fastener element 52 are disposed while shifted in the length direction to pass through different courses respectively.
Then, a sinker loop of the fixing chain stitch yarn 64 is inserted between the upper and lower leg portions of the fastener element 52, and the upper leg portion and the lower leg portion of the fastener element 52 are pressed and fixed by different second needle loops 64b respectively.
In the knitted fastener stringer 50 of Patent Document 1 configured as above, since the first needle loop 64a of the fixing chain stitch 64 is knitted into the ground structure of the element attaching portion 51a, the element attaching portion 51a of the fastener tape 51 can be formed in a dense structure. Furthermore, the upper and lower leg portions of the fastener element 52 are fastened and fixed by the second needle loop 64b of the fixing chain stitch yarn 64, and in this particular embodiment, the upper leg portion and the lower leg portion are fixed by the different second needle loops 64b respectively. As a result, according to Patent Document 1, the stretch property of the element attaching portion 51a of the fastener tape 51 becomes pretty much lost, and the fastener element 52 can be fixed to the element attaching portion 51a in a dimensionally stable state.
In Patent Document 1, a knitted fastener stringer 55 shown in FIG. 12 is disclosed as another example. In this knitted fastener stringer 55, the fixing chain stitch yarn 64 of a double structure is knitted into an element attaching portion 56a of a fastener tape, and the fixing chain stitch yarn 64 comprises two first and two second needle loops 64a, 64b at each one pitch of the fastener element 52 to form the element attaching portion 56a of the fastener tape in a dense structure.
In this case, a pair of upper and lower leg portions of the fastener element 52 are formed while overlapped in a tape front and rear direction to pass through the same course, and the pair of upper and lower leg portions are fastened and fixed to the element attaching portion 56a by the second needle loop 64b by being inserted into the alternate second needle loop 64b at the same time.
Thus, in the knitted fastener stringer 55 according to this another example, the second needle loop 64b fixing the upper and lower leg portions of the fastener element 52 to the fixing chain stitch yarn 64 and the second needle loop 64b not fixing the upper and lower leg portions are disposed alternately. Even in this knitted fastener stringer 55, the stretch property of the element attaching portion 56a of the fastener tape becomes pretty much lost, and the fastener element 52 can be fixed to the element attaching portion 56a in a dimensionally stable state.